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Health professional risk communication

SynchroMed II Implantable Drug Infusion Pumps - Urgent Medical Device Correction Letter - For Health Professionals

Starting date:
July 5, 2011
Posting date:
October 26, 2011
Type of communication:
Dear Healthcare Professional Letter
Subcategory:
Medical Device
Source of recall:
Health Canada
Audience:
Healthcare Professionals
Identification number:
RA-170002539

This is duplicated text of a letter from Medtronic of Canada Ltd.
Contact the company for a copy of any references, attachments or enclosures.

Notice about Health Canada advisories

Health Canada Endorsed Important Safety Information on SynchroMed II Implantable Drug Infusion Pumps

July 5, 2011

Subject: Urgent: Medical Device Correction: Battery Performance of the Model 8637 SynchroMed® II Implantable Drug Infusion Pumps

Urgent: Medical Device Recall [NJS_FILE:6e5a40a6-dfcc-4841-89fd-157b05f7a8d6:fe001347-7204-499c-b7a5-1711ad912495] to the 2009 Communication

Dear Healthcare Professional,

On July 13, 2009, Medtronic sent a Medical Device Correction letter to Healthcare Professionals regarding the potential for reduced battery performance that could lead to sudden loss of therapy in a small percentage of Medtronic Model 8637 SynchroMed® II pumps. The purpose of this communication is to provide you with updated information regarding the scope and occurrence of this issue, and to re-emphasize previously communicated patient management recommendations. Medtronic is not retrieving the SynchroMed II pump from the field or recommending prophylactic replacement of the devices.

Nature of the Device Issue:
Reduced battery performance is caused by the formation of a resistive film within the SynchroMed II pump battery. Pumps may exhibit Low Battery Reset (critical alarm), premature Elective Replacement Indicator (non-critical alarm), or premature End of Service (critical alarm). For affected pumps, the minimum timeframe of 90 days between Elective Replacement Indicator and End of Service may also be reduced. Refer to the enclosed Pump Event Information for: 1) a description of Low Battery Reset, Elective Replacement Indicator, and End of Service, and 2) screenshots depicting how the Medtronic N'Vision® Model 8840 clinician programmer displays these events.

Potential Severity of the Issue:
A patient with a pump exhibiting reduced battery performance may experience return of underlying symptoms and/or withdrawal symptoms. Patients receiving intrathecal baclofen therapy are at risk for baclofen withdrawal syndrome, which can lead to a life threatening condition if not promptly and effectively treated. One patient death (outside Canada) has been attributed to this issue, and it was determined to be due to baclofen withdrawal syndrome. For information on other drugs, please refer to the product labeling for the drug being administered. Patients with pumps experiencing Low Battery Reset or premature Elective Replacement Indicator due to this issue will require surgical revision to replace or remove their pump.

As of May 31, 2011, there have been 55 confirmed cases from approximately 139,653 SynchroMed II pump implants worldwide. One of the confirmed cases occurred in Canada. Returned product analysis of these pumps showed that the alarms were functioning as designed.   The SynchroMed II pump was designed to last up to 84 months.

SynchroMed II pump
Issue Confirmed OccurrencesTable 1 footnote * Implant Duration at time of issue

Table 1 footnotes

Table 1 footnote 1

* All but one of the reports occurred in pumps with batteries manufactured prior to March 17, 2005.

Return to table 1 footnote * referrer

Low Battery Reset 45 45 - 78 months
Premature Elective Replacement Indicator 10 47 - 77 months

Scope:
Pumps with batteries manufactured prior to March 17, 2005: As of May 31, 2011, statistical analysis of the confirmed cases has estimated the cumulative probability for pump failure due to this issue to be 1.1% at 84 months post implant with an upper bound estimate of 1.9%. Note that this 1.1% cumulative probability applies to a patient newly implanted, and reflects the risk over the full 7 years of expected pump life. The majority of pumps currently implanted were manufactured 6 years ago and therefore the probability for pump failure between now and end of service life is less than 1.1%. These rates are within the overall rates estimated in the July 2009 communication.

Pumps with batteries manufactured on or after March 17, 2005:  As of May 31, 2011,statistical analysis of the confirmed case has estimated the cumulative probability for pump failure due to this issue to be 0.03% at 72 months post implant with an upper bound estimate of 0.2%.

For additional detail on SynchroMed II failure rates and survival analyses, refer to the enclosed Pump Survival document.

To identify affected batteries, using the pump serial number, please visit the Medtronic web site. Alternatively, you can obtain a list of affected units specific to your clinic by e-mailing Medtronic directly at stephanie.a.johanson@medtronic.com.

Recommendations:

Medtronic does not recommend prophylactic replacement of SynchroMed II pumps because of the estimated low occurrence rates, the presence of pump alarms, and the risks associated with replacement surgery. This position has been reviewed and is supported by an experienced external physician panel. However, appropriate consideration should be given to individual patient medical needs. When the critical or non-critical alarms noted below occur, Medtronic strongly recommends that replacement surgery be scheduled as soon as possible for these patients.

Refer to the enclosed Pump Event Information for: 1) a description of Low Battery Reset (critical alarm), Elective Replacement Indicator (non-critical alarm), and End of Service (critical alarm), and 2) screenshots depicting how events are displayed and reported with the N'Vision Model 8840 clinician programmer.

If Low Battery Reset (critical alarm) Occurs: Replacement surgery should be scheduled as soon as possible. Although you may be able to reprogram the pump, the issue may reoccur at any time. Alternative medical management should be considered if appropriate.

If premature Elective Replacement Indicator (non-critical alarm) or End of Service (critical alarm) Occurs: Replacement surgery should be scheduled as soon as possible. In the case of premature Elective Replacement Indicator, the minimum timeframe of 90 days between Elective Replacement Indicator and End of Service may be reduced due to this battery issue. The date for scheduled replacement of the pump that is displayed on the Model 8840 N'Vision clinician programmer may not be accurate for those pumps experiencing reduced battery performance. Alternative medical management should be considered if appropriate. Elective Replacement Indicator may be considered premature if it occurs sooner than expected based on implant duration and flow rate.

Contact Medtronic Technical Services (1-800-707-0933) for assistance determining if an Elective Replacement Indicator message can be considered premature.

Ongoing Patient Management Recommendations:

  • Increase the critical alarm frequency to improve the probability of early identification of a Low Battery Reset (critical alarm) condition. Medtronic recommends changing the critical alarm interval frequency to sound every 10 minutes.  Refer to the enclosed Alarm Information sheet for details.
  • Remind patients, their caregivers, and your appropriate staff members to be alert for pump alarms. At implant or follow-up visits, perform an alarm test to provide an opportunity for patients and caregivers to hear and differentiate between the critical and non-critical pump alarms. Refer to the enclosed Alarm Information sheet for details.
  • Reinforce with patients and caregivers information on the signs and symptoms of withdrawal due to therapy cessation, and the importance of contacting their provider immediately. Patients receiving intrathecal baclofen therapy are at higher risk for adverse events, as baclofen withdrawal can lead to a life threatening condition if not promptly and effectively treated.
  • Inform patients about the importance of keeping their pump refill appointments and contacting their physician immediately if their pump alarm sounds or if they notice a change in symptoms. Remind patients to always carry their patient identification card.
  • A sample patient informational letter is attached for use with your patients.

Additional Information:

Health Canada has been informed.

Managing marketed health product-related adverse incidents depends on health care professionals and consumers reporting them. Reporting rates determined on the basis of spontaneously reported post-marketing adverse incidents are generally presumed to underestimate the risks associated with health product treatments. Any incidents of Low Battery Reset (critical alarm), premature ERI (non-critical alarm) or premature End of Service (critical alarm), or other serious or unexpected adverse incidents for medical devices in patients using one of Medtronic drug infusion systems should be reported to Medtronic, or to Health Canada at the following address:

Medtronic of Canada Ltd.
99 Hereford St.
Brampton, Ontario  L6Y 0R3
Telephone:  1-800-268-5346

Any suspected adverse incident can also be reported to:
Health Products and Food Branch Inspectorate
Health Canada
Address Locator: 2003D
Ottawa, Ontario K1A 0K9
Telephone: The Inspectorate Hotline 1-800-267-9675

The Medical Devices Problem Report Form and Guidelines can be found on the Health Canada Web site.

For other medical device inquiries related to this communication, please contact Health Canada at:
Marketed Health Products Directorate
E-mail: mhpd_dpsc@hc-sc.gc.ca
Telephone: 613-954-6522
Fax: 613-952-7738

To change your mailing address or fax number, contact the Market Authorization Holder (Industry).

We are committed to answering your questions and keeping you informed. Medtronic continues to monitor post market performance and investigate this issue and will provide you with an update if our recommendations change.

As always, Medtronic requests you return any explanted products to Medtronic Returned Products Analysis. If you have questions please contact your Medtronic representative, or contact Medtronic Neuromodulation Technical Services at 1-800-707-0933. This important patient management information is also available at Medtronic - For Healthcare Professionals under the heading Product Advisory.

Sincerely,

original signed by

Terry Finley,
Sr. Director Head, Neck and Spine Division
Medtronic of Canada

Enclosures:

  • Pump Event Information
  • Pump Survival
  • Alarm Information Sheet
  • Sample Patient Letter
  • Physician Reply Card

Pump Event Information

SynchroMed® II Battery Performance
Event What it means Type of Alarm Therapeutic Effect

Table 2 footnotes

Table 2 footnote 1

* Note: safe state does not mean a clinically safe rate of infusion. The minimum rate mode in effect during a pump safe state is non-therapeutic and can result in loss of drug effect and/or drug withdrawal. Patients receiving intrathecal baclofen therapy are at higher risk for adverse events, as baclofen withdrawal can lead to a life threatening condition if not promptly and effectively treated.

Return to table 2 footnote * referrer

Table 2 footnote 2

** Note: ERI may be considered premature if it occurs sooner than expected based on implant duration and flow rate. Contact Medtronic Technical Services (1-800-707-0933) for assistance determining if an ERI message can be considered premature.

Return to table 2 footnote ** referrer

Low Battery Reset LBR LBR occurs when battery voltage momentarily drops below 1.975 volts. If the voltage drop causes any data loss or corruption in pump memory, a safe stateTable 2 footnote * event will be triggered, resulting in infusion at the minimum rate mode of 6 microliters/day (0.006 milliliters/day) rather than the previously programmed rate.

Although you may be able to reprogram the pump, the issue may reoccur at any time.
Critical If safe state is triggered, the pump will go into minimum rate mode: 6 microliters/day (0.006 milliliters/day) rather than the previously programmed rate. The minimum rate mode in effect during a pump safe state is non-therapeutic and can result in loss of drug effect and drug withdrawal.
Elective Replacement
Indicator
ERI ERI activates when the pump nears the end of its service life (EOS). At ERI, the pump continues to infuse at the programmed rate.   Non-Critical A normal pump will operate for a minimum of 90 days at rates up to 1.5 mL/day prior to EOS. In the case of premature ERITable 2 footnote **, the minimum timeframe of 90 days between ERI and EOS may be reduced. This means that the date for scheduled replacement of the pump that is displayed on the N'Vision® Model 8840 clinician programmer may not be accurate.
End Of Service EOS EOS activation indicates the pump has reached the end of its service life. At EOS, the pump permanently stops infusing, but telemetry is available until the pump battery is depleted. Critical Pump will permanently stop delivering drug.

Low Battery Reset

Low Battery Reset - 8840 N'Vision Programmer Screen1

Low Battery Reset - 8840 N'Vision Programmer Screen

Low Battery Reset - 8840 N'Vision Programmer Printouts2

Low Battery Reset - 8840 N'Vision Programmer Printouts

Safe state does not mean a clinically safe rate of infusion. The minimum rate mode in effect during a pump safe state is non-therapeutic and can result in loss of drug effect and/or drug withdrawal.

Elective Replacement Indicator

Elective Replacement Indicator - 8840 N'Vision Programmer Screen3

Elective Replacement Indicator - 8840 N'Vision Programmer Screen

Elective Replacement Indicator - 8840 N'Vision Programmer Printouts4

Elective Replacement Indicator - 8840 N'Vision Programmer Printouts

The minimum timeframe of 90 days between ERI and EOS may be reduced in an affected pump, thereafter the scheduled replacement date displayed on the Print Report may not be accurate.

End of Service

End of Service - 8840 N'Vision Programmer Screen5

End of Service - 8840 N'Vision Programmer Screen

End of Service - 8840 N'Vision Programmer Printouts6

End of Service - 8840 N'Vision Programmer Printouts

At EOS, the pump stops infusing drug. This will result in loss of drug effect and/or potentially drug withdrawal. Telemetry is available until the pump battery is depleted.

Pump Survival

SynchroMed® II Battery Performance

Figures 1 and 2 show the cumulative survival probability for SynchroMed II pumps from this battery performance issue by length of implant time. These graphs were generated using US device registration and returned product analysis data as of May 31, 2011.

  • As shown in Figure 1, SynchroMed II pumps in the before group (pumps with batteries manufactured prior to March 17, 2005) show 98.9% survival from the battery performance issue 84 months post implant.
  • As shown in Figure 2, SynchroMed II pumps in the after group (pumps with batteries manufactured on or after March 17, 2005) show 99.97% survival from the battery performance issue 72 months post implant.

Pump Survival - Figure 1

Pump Survival - Figure 1

Pump Survival - Figure 2

Pump Survival - Figure 2

Kaplan-Meier Survival Estimates By Group
Period Implant Duration (Months)
Group 48 60 72 84
Before 99.97% 99.7% 99.3% 98.9
After 100% 100% 99.97%  

Refer to the Product Performance Report for more information on the overall reliability of the SynchroMed II pump. This is available at Medtronic - For Healthcare Professionals.

Alarm Information Sheet

SynchroMed® II Battery Performance

Alarm Information Sheet - N'Vision Model 8840 Clinician Programmer Screens9

Alarm Information Sheet - N'Vision Model 8840 Clinician Programmer Screens

The pump has two different alarms, a critical (dual tone) alarm and a non-critical (single tone) alarm.
Alarm Type Alarm Sound Alarm Meaning Available Intervals
Critical Dual tone Pump has stopped or will stop soon; immediate physician attention is needed 10 minute increments from 10 minutes to 2 hours
Non-critical Single tone Not as urgent; prompt physician attention is needed 1 hour increments from 1 to 6 hours

Sample Patient Letter

July 2011

Dear (patient name),

Medtronic recently updated doctors about a possible battery issue in a small percentage of SynchroMed® II drug pumps. You may have already heard about this issue. It was first shared with doctors in 2009.

What you should know about this issue:

  • Medtronic calls this the "battery performance" issue.
  • The chance of this happening is low.
  • If this occurs it may affect drug delivery and your pump alarm will sound.
  • If an alarm sounds or your symptoms return, it is very important that you call our office as soon as possible.
  • Medtronic recommends early pump replacement if your alarm sounds because of this issue.

Important reminders:

Pump Alarms

  • Your pump has two different alarms, a three-second two-tone alarm and a one-second single-tone alarm.
    • The two tone alarm means your pump has stopped or will stop soon. This requires immediate physician attention.
    • The single tone alarm is not as urgent as the two tone alarm, but still requires prompt physician attention.
  • Our office can perform an alarm test if you are unsure of what the alarms sound like.

Pump Management

  • Be aware of the signs and symptoms of withdrawal for the drug in your pump.
  • Keep all scheduled refill appointments.
  • Contact us immediately if you hear your pump alarm or if you notice a change in symptoms.
  • Always carry your patient identification card.

Please contact our office at XXX-XXX-XXXX if you have further questions or concerns.

Sincerely,

Physician Reply Card

FA 070511

Physician/HCP Reply Record (CCR)
Medtronic Model 8637 SynchroMed® II Battery Performance
2011 - Urgent Medical Device Correction

Customer name

Hospital

City

I confirm that I have received the Dear HCP Letter and the enclosures and fully understand the contents.

Signature

  • I wish to have a Medtronic representative contact me to discuss this further.

Instructions:

Please fax this form back to Stephanie Johanson / Rachel Shilletto at 1-905-460-3999.

Battery Performance July 2011


Long Descriptions

Long Description 1

Low Battery Reset - 8840 N'Vision Programmer Screen

This figure shows a screenshot depicting how the Medtronic N'Vision Model 8840 clinician programmer displays the Low Battery Reset event. Under the "Patient Information" section in the Attention Dialog Box, a notification appears reading "Pump in Safe State, Reset Occurred." The Pump Status Screen shows infusion mode at "Minimum Rate."

Return to long description 1 referrer

Long Description 2

Low Battery Reset - 8840 N'Vision Programmer Printouts

This figure shows the printouts when the Medtronic N'Vision Model 8840 clinician programmer experiences the Low Battery Reset event. In the Print Report, below the Current Pump Settings it reads "Reset Occurred." The Event Log specifies it was a low battery reset by displaying "Reset Occurred - Low Battery."

Return to Long Description 2 referrer

Long Description 3

Elective Replacement Indicator - 8840 N'Vision Programmer Screen

This figure shows a screenshot depicting how the Medtronic N'Vision Model 8840 clinician programmer displays the Elective Replacement Indicator event. Under the "Patient Information" section in the Attention Dialog Box, a notification appears reading "ERI Occurred," and recommends a date to schedule pump replacement by. The Pump Status Screen shows the same information. The date provided for replacement in both the Attention Dialog Box and the Pump Status Screen is calculated as a 90 day window from the current date.

Return to Long Description 3 referrer

Long Description 4

Elective Replacement Indicator - 8840 N'Vision Programmer Printouts

This figure shows the printouts when the Medtronic N'Vision Model 8840 clinician programmer experiences the Elective Replacement Indicator Event. In the Print Report, it reads "ERI Occurred," and recommends a date to schedule pump replacement by. Further down the page it gives the date of occurrence of the ERI. On the Event Log, it specifies the time and date during which the ERI occurred.

Return to Long Description 4 referrer

Long Description 5

End of Service - 8840 N'Vision Programmer Screen

This figure shows a screenshot depicting how the Medtronic N'Vision Model 8840 clinician programmer displays the End of Service event. Under the "Patient Information" section in the Attention Dialog Box, a notification appears reading "Terminal Event has occurred in the Pump, EOS Occurred." The Pump Status Screen shows the same information.

Return to Long Description 5 referrer

Long Description 6

End of Service - 8840 N'Vision Programmer Printouts

This figure shows the printouts when the Medtronic N'Vision Model 8840 clinician programmer experiences the End of Service Event. In the Print Report, it reads "EOS Occurred." In the Event Log, it specifies the time and date during which the EOS occurred.

Return to Long Description 6 referrer

Long Description 7

Pump Survival - Figure 1

This figure shows the cumulative survival probability for SynchroMed II pumps from this battery performance issue by length of implant time for the Before Group (prior to March 17, 2005). SynchroMed II pumps in the before group show 98.9% survival from the battery performance issue 84 months post implant.

Return to Long Description 7 referrer

Long Description 8

Pump Survival - Figure 2

This figure shows the cumulative survival probability for SynchroMed II pumps from this battery performance issue by length of implant time for the After Group (on or after March 17, 2005). SynchroMed II pumps in the after group show 99.97% survival from the battery performance issue 72 months post implant.

Return to Long Description 8 referrer

Long Description 9

Alarm Information Sheet - N'Vision Model 8840 Clinician Programmer Screens

This figure shows screenshots depicting how the Medtronic N'Vision Model 8840 clinician programmer displays the Alarm Test (Critical Alarm Test and Non-Critical Alarm Test) and the Alarm Intervals that can be changed. To access the Alarms Intervals, select the Alarm tab. The desired alarm intervals for both Critical and Non-Critical Alarms can be set here. By selecting the toolkit tab, buttons are available to sound the pump alarm as a test. A critical alarm is of dual tone and indicates that the pump has stopped or will stop soon. This requires immediate physician attention. A non-critical alarm is of single tone and is not as urgent; prompt physician attention is needed.

Return to Long Description 9 referrer

Images

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